Java JFrame：Windows 布局和嵌入

Question

我需要为 Jframe Window 定义一个布局，如上图所示。

以下是我的方法。 来自我的资源文件夹 (/resources/...jpg) 的图片嵌入在中间 (main) 中。 Top、Bottom、Left、Right 分为四个部分，而它们的内容是一个被拉伸的带标签的按钮，所以我可以稍后在上面映射一些方法，改变主容器内的图片。

我试图显示图片，但我得到了您在我的屏幕截图中看到的结果。我在主容器中看不到它，也没有收到错误消息。

我不知道这是否是因为我使用 JFrame 的方法错误。 下面你可以看到我的代码，如果你也能帮助我解决我错误的设计布局模式，我会很高兴。

MyFrame.java

package ms0.gui;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.border.*;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class MyFrame extends JFrame {
    public MyFrame () {
        setTitle("This is an example title");
        setSize(600,600);
        setLocation(750,640);
        setVisible(true);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        
    
        
        
        //Main Container
        Container mainContainer = this.getContentPane();
        mainContainer.setLayout(new BorderLayout(8,6));
        mainContainer.setBackground(Color.BLUE);
        this.getRootPane().setBorder(BorderFactory.createMatteBorder(4, 4, 4, 4, Color.green));
        
        
        //JButton Positions
        JButton topButton = new JButton("Oben");
        JButton bottomButton = new JButton("Unten");
        JButton leftButton = new JButton("Links");
        JButton rightButton = new JButton("Rechts");

        
        //Panel Top
        
        JPanel topPanel = new JPanel();
        topPanel.setBorder(new LineBorder(Color.BLACK, 3));
        topPanel.setBackground(Color.ORANGE);
        topPanel.setLayout(new FlowLayout(5));
        topPanel.add(topButton);
        mainContainer.add(topPanel, BorderLayout.NORTH);
        
        //Panel Middle
        
        JPanel middlePanel = new JPanel();
        middlePanel.setBorder(new LineBorder(Color.black, 3));
        middlePanel.setLayout(new FlowLayout(4,4,4));
        middlePanel.setBackground(Color.cyan);
        
        
        //Grid Panel Right
        JPanel rightPanel = new JPanel();
        rightPanel.setLayout(new FlowLayout(4,4,4));
        rightPanel.setBorder(new LineBorder(Color.black, 3));
        rightPanel.setBackground(Color.GREEN);
        rightPanel.add(rightButton);
        
        
        //Grid Panel Left
        
        JPanel gridPanel = new JPanel();
        gridPanel.setLayout(new GridLayout(4,1,5,5));
        gridPanel.setBorder(new LineBorder(Color.black, 3));
        gridPanel.setBackground(Color.red);
        gridPanel.add(leftButton);
        
        
        
        //Center Box
        JLabel label = new JLabel("Center Box", SwingConstants.CENTER);
        label.setOpaque(true);
        label.setBorder(new LineBorder(Color.black,3));
        
        middlePanel.add(gridPanel);
        mainContainer.add(label);
        mainContainer.add(middlePanel, BorderLayout.WEST);
        mainContainer.add(rightPanel, BorderLayout.EAST);

        
        //Panel Bottom
        JPanel bottomPanel = new JPanel();
        bottomPanel.setLayout(new FlowLayout(3));
        bottomPanel.add(bottomButton);
        bottomPanel.setBackground(Color.magenta);
        bottomPanel.setBorder(new LineBorder(Color.BLUE, 3));
        mainContainer.add(bottomPanel, BorderLayout.SOUTH);
        
    //Siegel
    
        
        
            String filepath = "/resources/siegel.jpg";      
            int picWidth = 150;
            int picHeight = 150;
            
            ImageIcon image1 = new ImageIcon(getClass().getResource(filepath));
            //Image scaledImage = img.getScaledInstance(picWidth, picHeight, Image.SCALE_DEFAULT);
            //ImageIcon icon = new ImageIcon(scaledImage);
            
            mainContainer.add(new JButton(image1));
    
    
    }
}

Answer 1

所以，作为一个非常基本的例子，除了BorderLayout

import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;

public class MyFrame extends JFrame {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                MyFrame frame = new MyFrame();
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public MyFrame() {
        setTitle("This is an example title");
        setDefaultCloseOperation(EXIT_ON_CLOSE);

        setLayout(new BorderLayout());

        add(new JButton("Top button (stretched)"), BorderLayout.NORTH);
        add(new JButton("Left button (stretched)"), BorderLayout.WEST);
        add(new JButton("Right button (stretched)"), BorderLayout.EAST);
        add(new JButton("Bottom button (stretched)"), BorderLayout.SOUTH);

        JLabel label = new JLabel("Picture");
        label.setBorder(new EmptyBorder(100, 100, 100, 100));

        add(label);
    }
}

记住，简单往往是最好的。

现在，如果您绝对肯定必须将标签/图片放在另一个容器中，您可以简单地使用GridBagLayout，因为它默认将子组件居中，例如...

JLabel label = new JLabel("Picture");
label.setBorder(new EmptyBorder(100, 100, 100, 100));

// Automatic center position
JPanel mainPane = new JPanel(new GridBagLayout());
mainPane.add(label);

add(mainPane);

而且您不必使用EmptyBorder。 GridBagLayout 将允许提供 insets 这将做同样的事情